Sustainable options for mitigation of major toxicants originating from electronic waste

Electronic waste (e-waste) is an emerging source of toxic contaminants in the environment. It is considered to be hazardous as it is known to contain toxic metals, viz. Cr, Ni, Zn, Pb and Hg in huge amounts and organic pollutants, viz. polychlorinated biphenyls, polybrominated diphenyl ethers and tetrabromobisphenol-A. Rapid development and changes in lifestyle have resulted in a huge pile-up of e-waste and its continuous production further makes the situation troublesome. E-waste is usually processed informally for recovery of precious metals. During this process, a large amount of toxic metals, organic compounds and secondary organic pollutants such as polyaromatic hydrocarbons and dioxin enters into the environment. Disposal of raw or processed e-waste in landfills also results in contamination of soil and groundwater through leachate. Considering the present environmental condition along with toxic and persistence nature of pollutants originating from e-waste, their remediation using sustainable methods is highly desirable. This article provides an overview of different bioremediation options used and available for remediation of e-waste-related pollutants. Advantages and limitations of these methods along with their applicability in restoration of contaminated system are also highlighted.